Generally, a glass panel or a side fixed glass panel (e.g. for vehicles) is integrated with a synthetic resin mold having a predetermined shape so as to increase the strength of the glass panel and to allow the glass panel to be efficiently coupled to a packing The process wherein the synthetic resin mold is integrated with the edge of the glass panel is referred to as glass encapsulation. However, “glass encapsulation” as used herein is not limited to any particular intended use or specific part-making operation. Glass encapsulation, as used herein, refers generally to rubber and EPDM injection molding in conjunction with one or more glass features and the various concerns and requirements associated therewith.
Rubber (EPDM) injection molds typically must be heated to approximately 350° to 410° F. to allow the injected material to cure or vulcanize properly. Accordingly, individual pieces of a mold that form a cavity in which the rubber is injected must be fit together with extreme precision. Excessive gaps between such mold portions can result in undesired “flash” of excess rubber which must be removed prior to processing or further use of the part. Flash may also damage the mold.
In glass encapsulation mold applications, sealing of the mold to avoid flash is particularly difficult, as a pane of glass is typically inserted into and confined within the mold. The mold must therefore seal against the glass during injection and curing of the rubber to avoid flash without crushing or breaking the glass.
The thickness of inserted glass can vary on average by as much as ±0.3 mm or ±0.012″. To compensate for this thickness variation, molds may be designed to allow adjustment of the “glass gap”. The position of a mold part that seals against the glass (referred to herein as “glass saddle” or “glass insert” or) is adjustable. A known method of adjustment requires an exchange of fixed shims under the glass saddle. This in turn requires partial disassembly of the mold. Such processes are very time consuming and difficult due to the operating temperature of the mold and other factors. Additionally, such processes typically require accessing a tight, inaccessible, and dangerous location by operators. Accordingly, known processes are time consuming, inefficient, and pose a number of safety risks.